Fundamentals of Small Animal Nutrition

1. Fundamentals of Small Animal Nutrition Dr. Randy Ackman Nutrient Content of Pet Food

2. Nutrient Content of Pet Food • Two ways determine nutrient levels • Proximate analysis • Most accurate • Laboratory analysis on finished product • Provides percentages of • Moisture • Crude protein • Crude fat • Ash (minerals) • Fiber • NFE • Reports only maximums and minimums

3. Nutrient Content of Pet Food • Calculation Method • Calculation of the average nutrient content of the food’s ingredients using values reported in tables • Amount of essential nutrients in each ingredient is summed • Less costly • Less time consuming • Significant sources of error

4. Nutrient Content of Pet Food • Downfalls of calculation method • Lack of complete and accurate data for many nutrients in commercial dog food • Tables contain approximations • Table may be out dated • Grain yields increase protein levels decrease • Corn average protein content is 7.87% • Range of 5.97% to 10.25% • Also in oats, sorghum

5. Nutrient Content of Pet Food • Downfalls of calculation method (cont) • Quality of ingredients cannot be determined and is not considered • Quality of ingredients affects • Availability • Standard tables reflect averages • Processing affects quality of nutrients • Nutrient loss • Digestibility • Availability

6. Nutrient Content of Pet Food • Determination of Digestibility • AAFCO does not require companies to list digestibility • Digestibility • Measure of diet’s quality because it directly determines proportion of nutrients in the food available for absorption • Measured through feeding trials • Measure disappearance of nutrients as they travel through GI tract

7. Nutrient Content of Pet Food • Digestibility • Test diet fed pre –test (5-7 days) • Amount of food fed is measured • Amount of fecal material excreted is measured • Nutrients of each are measured • Expressed as percentages • Called digestion coefficient • Apparent digestive coefficients • Fecal matter contains waste not from the food

8. Nutrient Content of Pet Food • True digestibility measured by • Deducting normal metabolic loss of the nutrient from the amount of the nutrient measured in the fecal matter • Usually done for protein • Low- protein to protein free diets fed for baseline • Cellular loss • Enzymatic loss

9. Nutrient Content of Pet Food • Current AAFCO standard is calculation method • If digestibility trials used to determine ME values • Cannot vary 15% of calculation method http://www.high-tech.com/panther/images/panthmm1.jpg

10. Nutrient Content of Pet Food • Expression of Nutrient Content • AF = as fed • DMB = dry matter basis • Water dilutes nutrients • 25% protein • 25% moisture semisolid food • 10% moisture dry food • Calculate % protein on dry matter basis http://www.nald.ca/FULLTEXT/numboost/percents/percent5/graphics/percent.gif

11. Nutrient Content of Pet Food • Nutrient Density • Calculating levels of nutrients as a proportion of ME • Most accurate • Allow accurate comparison to all foods • DMB does not differentiate between energy content only water • Why is this important? • Accounts for differences in • Water and energy content

12. Nutrient Content of Pet Food • Nutrient Density • Expressed as a percentage of ME or • g/1000kcal of ME or • Units /1000kcal of ME if vitamin or mineral • p171 • Marginal vs high protein diet • Obesity or protein deficient • Applies to all nutrients

13. Nutrient Content of Pet Food • Balance diet so that • When caloric requirements are satisfied • All nutrients are met at same time • Express nutrient density as • % of ME or units per 1000 kcal ME • Avoid percentage by weight

14. Nutrient Content of Pet Foods • Comparison of Calorie distribution • Hard working dogs require • High protein to maintain muscle • Higher fat content • For example • Protein 32%, fat 56%, and carbohydrate 12% of ME calories • Less active dogs • Less protein and less fat • Protein 26%, fat 38%, and carbohydrate 36% of ME calories • Growing dogs • Protein 27%, fat 41%, and carbohydrate 32% of ME caloires

15. Nutrient Content of Pet Food • Calculating ME/ kg • Crude protein not less than 26% • Crude fat not less than 15% • Crude fiber not more than 5% • 100%- 26%-15%-5%-7%(mineral-ash)=47% • Use modified Atwater conversions • Calories per 100g of food = 383 kcal • Calories of ME per kg of the food is 3830 kcal

16. Nutrient Content of Pet Food • Common Pet Food Ingredients • Ingredient list • Cannot reference quality • Diet must conform to pet food label • Identify source of nutrient • Protein • A contributor of protein if protein content of ingredient (%) is greater than protein content of diet (%) • Ingredient is a protein source

17. Nutrient Content of Pet Food • Protein Sources • Plant sources • Animal sources • Combination of both • Animal protein • Superior amino acid quality (high quality) compared to plant protein • Ranges from excellent quality to poor quality • Plant (grain) protein • Consistent in ability to supply amino acids

18. Animal Protein Beef Chicken Chicken byproduct meal Chicken meal Dried egg Fish Fish meal Meat and bone meal Meat byproducts Meat meal Lamb Lamb meal Rabbit Nutrient Content for Pet Food

19. Nutrient Content of Pet Food • Meat • Any species of slaughtered mammal • Pork, beef, sheep, horse etc • Combination of flesh, skin, +/- bone • Byproduct • Secondary products are included • Ie parts of carcasses may contain • Bone, head, viscera, feet, but no feathers

20. Nutrient Content of Pet Food • Meal • Any ingredient that has been ground or otherwise reduced in particle size • Ie chicken meal • Dry ground whole chicken exclusive of heads, feet, viscera

21. Nutrient Content of Pet Food • Grain protein sources • Corn gluten meal • Soy flour • Soy grits • Soybean meal • Alfalfa meal • Flax seed meal • Wheat germ

22. Nutrient Content of Pet Food • Corn gluten meal • Dried residue after starch has been removed and bran has been separated • Relatively consistent in quality • Not as digestible as high-quality animal protein • High proportion on DM basis • Deficient in lysine and tryptophan

23. Nutrient Content of Pet Food • Soybean Products • TVP • Meal, flour, grits • 70-87 % digestibility • Limiting in methionine • Rich in lysine • Complements corn meal gluten

24. Nutrient Content of Pet Food • Soy • Protein well digested • CHO portion is poorly absorbed • Fermented in colon by bacteria • Production of SCFA and gas • Osmotic action • Yields loose stools and flatulence • Due to oligosaccharides

25. Nutrient Content of Pet Food • Raw soy • Phytate • May inhibit absorption of nutrients • Trypsin inhibitors • Heat labile and destroyed during processing • Hemagglutinins • Also destroyed upon heating

26. Carbohydrate sources Corn Rice Grain sorghum Wheat Oats Lesser Barley Carrots Flax seed Molasses Peas Potatoes Nutrient Content of Pet Food In form of starch

27. Nutrient Content of Pet Food • Carbohydrates • Cooking • Greatly increases digestibility of starch • Dietary fiber • Not digested • Included with carbohydrates • Sources • Beet pulp, rice bran, apple and tomato pomace, peanut hulls, citrus pulp, oat bran, rice, and wheat • Pulp • Residue after juices have been extracted • Pomace • Pulp of fruit

28. Nutrient Content of Pet Food • Fat source • Fat and essential fatty acids • Enhances palatability • Animal fats and oils • Animal fat = fat that comes form tissues of animals or poultry • 90% total fatty acids • Poultry fat or beef fat • Single type of animal fat • Animal fat • More than one source of animal fat

29. Nutrient Content of Pet Food • Fat sources • Vegetable fat • Vegetable oil extracted from plant seeds • Corn, safflower, soybean • Flax seed • Excellent source of omega-3 fatty acid linolenic acid • Borage oil • Linolenic acid and omega 6 fatty acid

30. Nutrient Content of Pet Foods • Vitamin and Mineral Sources • Purified forms only in small amount • Most are present in other nutrients • Low on ingredient list • Consider • Bioavailability • Adequate amounts • Relationship between minerals • Ie excess Ca, Cu, and Vit D inhibit absorption of Zn

31. Nutrient Content of Pet Food • Vitamins and minerals • Loss during processing and storage • High heat in canning • Loss in B vitamins thiamin and folic acid • Extrusion • Vitamin A, riboflavin, folic acid, niacin, and biotin

32. Sources of Vitamins and minerals Potassium chloride Calcium carbonate Dicalcium phosphate Monosodium phosphate Manganese sulfate Copper sulfate Zinc oxide Ferrous sulfate D-activated animal sterol Alpha-tocopherol Thiamin Niacin Calcium pantothenate Pyridoxine Folic acid Biotin Nutrient Content of Pet Food

33. Nutrient Content of Pet Food • Additives and preservatives • Additives • Are included in pet foods • Preserve products • Color • Flavor • Texture stability • Nutrient content

34. Nutrient Content of Pet Food • Product must through out shelf life be • Free of toxin • Free of contamination (bacterial) • Proven nutritious • Safe for consumption

35. Nutrient Content of Pet Food • Preservatives • Dry food • Low moisture inhibits growth • Canned food • Heat sterilization and anaerobic conditions • Semimoist • Low pH • Humectants bind water • Makes unavailable for bacteria • Chemicals • Potassium sorbate

36. Nutrient Content of Pet Food • Most important preservative • Antioxidant – preserves fat (animal, plant, ADEK) • Prevents oxidative degradation (lipid peroxidation) • Three stages • Initiation • Free radical (usually oxygen) attacks a PUFA resulting in formation of fatty acid radical • Then reacts with more oxygen to form peroxide • Propagation • Autocatlalzes until FAs are gone • Decomposition • Offensive odors, tastes • Loss of calories • Toxin formation

37. Nutrient Content of Pet Food • Types of antioxidants • Natural derived • Found in vegetable oils and some grains • Vitamin E • Alpha good biologically • Gamma, delta better antioxidants • Vitamin C • Synthetic • BHT – butylated hydroxytoluene • BHA - butylated hydroxyanisole • TBHQ – tertiary butylhydroquinine